Ore beneficiation



flotation.

employed.

Broadly stated our invention comprises a process for a r 2,944,666 1C resented July 12, 1960 ammour: BENEF'Iic -A Q Fred Henry. Bunge. and: Ivan George Eocrnich, Hibbing,- Minna, assignorsto TheM. AsHHIIMQOIBPaIiY, Clev'e land; Ohio; a-corporationof- Ohio 1 a No Drawing. Filed Apr. 4, 1956, Ser. No. 575,938

13 Clalrnssr (Claw-5) This invention relates as indicat'ed'lto the of. ore beneficiation and more specifically. to a. process for separating. iron-oxygen. compounds frormironbearing, ores by Iron ores, immediately. .aret rnined, contain excess quantities of siliceous gangue which make direct 2i the. presence, of a. carboxylic' acid collector and fuel oil, it is foun'd'that these fine sizes of iron are heavily floc culated so that they gather" in heavy blackpmasses, while the fihe sizes of. gan'gue are well. dispersed in the ore.

In the subsequent flotation of the ground ore,.these. floccul'ated masses of, fine i'ronparticles are carried to the surface in the froth, and. the dispersed gangue particles reniainiin the, tailing. The exact reason. for this flocculation of. the fine iron particles is. not completely understood at. present- However, when the ore. is ground in the presence of the reagents the fine sizes of iron are floated to the surface with. the remainder. of, the. heavy iron concentrates leaving the gangue particles in the tail= ing. For. this reason, it is. not necessary to removev the fine particles from ore treated according to our invention. The fine iron particles are collected in the concentrated iron froth, and the finegangue particles remain in transportation and smelting of the ores economically 1 impractical. For this reason, the ores are generally purified by such; processes. as ,flotationgx Many ore flotation processes have been proposed in the past, both to float the iron constituent of the ore from Zthe gangue and to float the gang'ue from the iron. These processes however, have been very inefficient inconcentrating ores containing high percentages of slimjes. Generallyin. order.

roducts= by ,these processes to produce acceptably pu'r it has been necessar'y to r ve the slirhes from the ore before it 'isfloated. The deslirning operations considerably increase the cost of the finished ore both" cause the deslirning operations ;.themselves require? W 'money'a'nd hecau'selthe.ironiconstituents of thejslimes are lost. e

It is 'therefore,- thelfprincipalobject ofthis ihvention 'to provide a process of ore'flot'a'tiofi ivhereby'substantially the tailings. I

The carboxylicacid collector used-may be any one of a number. of crude or refined fatty or resin acids. Crude fatty acids such as tall oil and acidulated cottonseed foots' have been found to be'good collectors to employ in the process of our invention; I The amount of car- .exceedih'glS lbs; per ton of ore.

- 'One' ofithe oils most. economical and easily. lobtainable" v for use-inthe-process of our'invention isthatllifeferred V l toiby the Yt'radeas' No. 2 fueloil. This oil is a petroleum nastieshaving a boiling point of between 450 and 670 all of the iron content of the ore will be collected with. Q

a minimum quantity of gangue. It is a more particular object of this inventiom to; provideta process of iron ore flotation. wherein. desliming. ofthe one isnot. necessary...

Other objects. and. advantages of the present invention will become. apparent asjthes following description proceeds.

To. the ends, said invention, then, comprises thefeatureshereinafter fully described and particularly pointed out in the claims, the following description setting fort-h in'.. detail certain illustrative embodiments of the invention-, these being indicative, however, of-fbut a? few' of 7 the. various ways in which the principle of the invention may be the recovery of iron-oxygen compounds from ironbearing ores which comprises grinding said 1 ore to flotation size in the presence of, Lto. 5 pounds of acarboxylic acid per tonv of solids and l. to 29: ounds: at an' oil.- .per ton of solids, and subjecting the. entire. mass which has thus been ground to froth flotation. t a

We have foundthat by grindingflironoresin tlie presence of a carboxylic acid; senator and. a'. hydrocarbon oil, substantially all of. the-iron.constituents of the ore may becollected by flotation- Iron orevvhieh has been ground without. reagents has 'ared color. which is char: acteristic of the. dispersed fine sizes.- of. hematite. It is recognized that. known.fiotation;processes do. not produce substantial quantities of gangue; materialis v When the ore is ground accordingto ourmvention in accomplishment. of. the. foregoing. andrelated F. and a flash point of 100 F. The amounts of fuel oil used in the process should be within the range of 1 to 20 lbs; of' oil per ton of solids, and in most cases, we have found that 7 to 10 lbs. of oil per ton of solids is most desirable. I

As indicated abovethe broad embodiment of our invention' comprisesgrin'ding' the ore in the presence ofthe reagents and subsequently floating the iron constituents thereof from thegangue in: a. bath of'water. Onsome ores we have found it desirable to preliminarily com? grinding the ore in the presence of, more reagents and subjecting the fine ground material to froth flotation. I

Concentrationofiron me by prior art processes has necessitated grindingofthe ore to at least approximately 65 mesh; However; We have found that iron particles as largefas 20m'esh may be floated by our process. The

I bestproducts are oh'tained'whe'nthe ore is ground to such an" extent'that' the iron is liberated from'the gangue.

- Grin'dingto 1'00 meshis generally sufl'icientfor the purpose. -O'f"'course,"the degreeofigrinding necessary. to obtain the-bestproduct-varies. with the typeofore being purified. For this reason no specific time limits for grinding can be stated. The required grinding varies for different ores.

Our process can be Varied to a considerable degree within the limits ofIour invention.. It is essential that the ore'be ground in the presence of the carboxylic acid collector and an oil, but otherreagents may beadded to the ore immediately prior to flotation and any of the well-known cleaning and finishing operations may be employedfafter the flotation. We have foundit desirable to add to the ground pulp just prior to flotation a small quantity ofsodium. silicatelor Orzan AH-3.

The following examples are included herein to more particularly illustrate specific methods of practicing our invention on given ores andtoillustrate itsadvantages overprior art processes.

3 EXAMPLE 1 A sample of Mesabi Range rock rejects was crushed to 10 mesh and the -10 mesh material ground in a laboratory rod mill to liberation size. In the grinding operation the sample-was ground for 15 minutes and then the reagent addition of the fuel oil and Aliphat 44B were made to the pulp in the rod mill. The pulp was then ground an additional five minutes with the reagents. The Aliphat 44B is a distilled tall oil produced by General Mills, Inc. After the'sample had been ground in'the presence of the collector and fuel oil, it was diluted to 13% solids. To the diluted pulp was added a small quantity of sodium silicate. Subsequent to the addition of the sodium silicate, a rougher flotation concentrate was skimmed from the flotation cell. The rougher flotation concentrate was then subjected to three cleaning operations to produce a concentrate of an acceptable grade. The test procedure and results obtained are presented in the following table.

Conditions and reagents Conditions 7 Reagents Pounds v V Per Ton Stage of Process Time, Per- Ali- N0. 2 So- Mincent pH phat Fuel dium utes Solids 44B 011 Silicate Red Mill Grind. Rod Mill Grind. Rougher Float-.. 1.Clea.ner. 2Cleaner. 3-Cleaner.

Metallurgical results Assay Percent Distri Product Weight Units button Percent Fe Percent Fe S10; Fe

Heads (Assayed) 36.97 Heads (Ca1eu1atcd) 100. 36. 69 100.0 Rougher Tailing 27. 5. 43 1. 47 4. 01 1 Cleaner Tailing 11.13 11.25 1.25 3. 41 2 Cleaner Tailing 5. 33 21. 53 1. 3. 13 3 Cleaner Tailing 3.09 32. 37 1. 00 2. 73 Concentrate; 53. 35 59. 65 31. 82 86. 72

EXAMPLE 2 Conditions and reagents Conditions Reagents Pounds per 7 Ton Stage of Process Time, Per- No. 2 Sodium Mincent pH Liqro Fuel Silicate utes Solids Oil Red Mill Grind" 67 N atural- 2. 34 8. 22 Rougher Float- 2% 26' 0. 1.Clea.ner 2-01eaner-.. -3-Cleaner..

Metallurgical results EXAMPLE 3 The sample of material used for this test is known as a specular hematite and was obtained from the Groveland formation. In this example, the collector and fuel oil were added tothe sample at the beginning of the grinding period. The collector used was acidulated cottonseed foots produced by The Southern Cotton Oil Company. In this test no sodium silicate was used.

- Conditions and reagents Conditions Reagents Pounds 3 er Ton 1 stage orPi-ocess Acidu- A Time, Percent lated No. 2

Minutes Solids pH Cottoln- Fuel Oil 1 i sec Foots Rod Mill Grind 15 61 Natural 2.20 7.68 Rougher Float 151 26 o 1Oieaner-. 152 do 2Cicaner 13 -do 3-Gleaner 7 o do Metallurgical results Assay Percent Distri- Product Weight Units bution Percent Fe Percent Fe S10, Fe

Heads (Assayed) 34. 97 :Heads (Calculate .00 g 35.05 100. 00 Rougher Tailing- .52 l 5.88 1. 91 5.45 l Cleaner Tailing .09 12. 65 1.15 3. 28 2 Cleaner 'Iaxlmg.- .10 21. O6 0.86 2. 45 .3 Cleaner Tailing .26 28. 49 0. 64 1. 83 Concentrate 03 58.60 30; i9 86. 99

7 EXAMPLE 4:

The sample used forrthis test was a drill core sample from the formation known as Felch Mountain; The crushed 10'mcsh material was ground in a laboratory rod mill for 15 minutes. The collector, Aliphat 44E,

a product of General Mills, Inc., and fuel oil additions were then made to the pulp in the rod .mill and the sample ground with the reagents 'for. an additional five minutes. The ground sample which had been conditioned "with they above-mentioned reagents during the last stages of the grind was pulped with water in -a laboratory flotation cell and a sodium silicate addition made to the pulp. A rougher concentrate was then removed by skimming the froth from the cell. In like manner, the rougher concentrate was cleaned threetimes by repulping with tap waters Sodium silicate additions were made to the first and second cleaner circuits I Conditions and reagents Reagents names EXAMPLE 6 r I A pplicat iono f summaries process to the large remetallurgical results obtained on the 1% inch *Halobe Cmditim serves of non-magnetic taconite found on the Mesabi PerTon Y y e a 5 Range is .shown' n Examples 6 and 7. The non-magnetic S a Process taconite sample used in these testswas obtained from the Time, Per- Ah: No.2 ,So; 7

I w v Mincent, pH phat: Fuel dium property known as West Patrick. In th s example,.the utes Sdlds' 44E on l f crushed 10 mesh material was ground in a lahoiatory rod mill for 20 minutes. The collector Liqro, which is M2 U a crude tall oil, and fuel oil additions were then made to RodM111Gr1nd t R'ougher Float the pulp in the rod-mllland the pulp ground an additional 1C1eaner fi e minutes with the reagents. The ground sample was 2-C1eaner H ,7 3-C1aner .hen pulped 1n a laboratory flotation cell and a sodium H I 'licate addition made to the pulp. 'The rougherfroth Metallurgical r'esults a t en k d, ro the flotation c :I 1;? enj 15 ner, the rougher concentrate was cleaned three t-i neshy T Assay-Percent. EM. repulp-mg with tap 'water. I Addit onal sodium silicate Product .Weight Units bution was added to the first and second cleaning circuits.

Percent A v Fe Percent V k V t e y Bfe s10; n r Fe I M Conditions and reagents V Heads (Assayed) 32. 72 Conditions Reagents Pounds per Heads (Calcu1ated) 100.00 32; 91 100. 00 a Ton Rougher Tailing 31.44 4:62 71. 15' -,4:41 x T 1 Cleaner Tailin 12.00 10.86 1.30 3.95 Stege'of Process I Y 1 2C1eanerTaili1w. 5.99 21.71 1.30 3.95 Time, .Per-

1 No.2 Sodium 3'C1eaner'1ailing. 3.40 31.42 $1. 07 3. Mincent pH Liqro Fuel Silicate Concentrate..- 1 47.17 58.91 27.79 84.44 25 utes Solids Oil 5 7 Rod'MillGrinnL. 2e 60 A d 9 salaried i i" 94 Rod Mill Grind.-- a Y 60 1.11 8.96 I Y a 26, 0.50 r lProdu't Fe I'SiQ "oao Mg 0 Mn- 1,03 P enemas. 60:70 6.70 2'66" 104i 0:50 0:12'

N a w -Mjet qllurgical results H EXAMPLE F 72.; 'Assay iei'cent Distri- '1:he invention is further described m this example 1 22533, si .ggggg where the process has beenapplied to various size frac- Fe 810, v Fe none of Mesabi Range ores which are tdo're'fractory fto be concentrated effectively by the conventional gravity 7 i methods which arefnowu'sed. Fo1-"e'Xamplethe 1 /zinch sagg- 93;;33 natural size particlesofanore'identif ed"as'Halobe when 40, 1 Cleane rfIaihng. 1o; 62 1.173 crushed "to /2" and "concentrated by the "conventional .Q l 1 v H n V I 3C1eanerTa1lin 0.51 1.42 heavy media method produced 'aconcentrate which as- Concentrate 33.46 93.39 sayed 54.00 percent iron'and2 2f73 Pereentsilica. I -Iow- 'e\ er, whena sample of the 1 /2' inch naturalsizeiparticies EXAMPLE 7 or the "or was crushed and -"ground t'o flotation; size and 45 The test shown in "this "example *is a duplicate "of "Ex- 'arnple 6 except that slightly decreased quantities of fatty acid and fuel'oil were used The conditions, reagents used, and metallurgical results of the test are presented ore 'is'p-resented in the followingftab'ulafion. 'imthe'fol'lowing table- Conditions anar 'az'hts i qi i s'ii d' Conditions I ii t'eaen ts i loundsber Conditions 'R-ehlgent-sqgglindsvpier Stage of Process Stage of Pwcess Ti P 'Time, 'Per- H No.2 Sodium g: g; H L1 qio 3 'Min- :cent -pH Liqro Fuel Silicate utes Solids- I, f: a. F W. 011 Rod M111 Grind; 20 in -Natural 2.54.. 8.22- 33 333g" 2 Rougher Float... 2 26'.' do 0.50 Rougher mead 2 -1Cleaner 2 do 0. 50

l 1 Cleaner.-. 2 2Cleaner 2 0.25 koleaner; 2 v 2 9- '3 Cieai1er 2 .M iq ht kd r tt et M ll r lts 7,

. Assay Per nt Distriv Assay Percent Distil- Product Weight Units bution Product Weight Unitsbution Percent v Fe .Percent Percent v Fe 7 Percent m l e S10; 7 n iie Fe SiOz Fe Heads (Assayed) I Heads (Assa y'ed) HeadsiCalculate 100.00 100.00 Heads (Calculated) 100.00 100; 00 Rougher Tailing 23. 15 .2. 65 Rougher Tailing 30. 83 '2. 91 1 Cleaner Telling.-. 10. 49 ,2. 59 1 Cleaner Tailing 11.77 3.00 2 Cleaner Tailing... 5.43 2. 21 2 Cleaner Tai1ing. 5.18 2. 91 -15 Cleaner 'iailing 3. 13 2.00 3 Cleaner Tailing.. 2. 89 .2555 Concentrate 57 90. 55 1 Concentrate 49. 33 88. 63

tional petroleum sulfonate process.

7 COMPARATIVE EXAMPLE OF PRIOR ART In order to further illustrate the improved results that .vention, a testwas conducted using the known conven- The test using the petroleum sulfonate procedure was performed on a sample of the same ore which was used in the test described in Example 1. It is well known that in order for the sulfonate process to function satisfactorily the fine sizes of ground ore frequently referred to as slimes must be first removed in order that their adverse effect on the subsequent flotation operation will be eliminated. The procedure and results obtained with the sulfonate process are presented in the following table. In conducting this test the 10 mesh ore was ground for 20 minutes in a rod mill. After grinding the sample was pulped to 20% solids, the fines were dispersed with sodium silicate and that an iron concentrate of an acceptable grade would be produced.

Conditions and reagents Conditions Reagents Pounds Per Ton Stage of Process Time, Per- Rea- Sul- Sod.

Mincent pH gent Fuel phur- Siliutes Solids 899 Oil ic cate Acid Rod Mill Grind.-- 20 .67 Deslime (2 times). 3 20 6. Condition 3 50 5. 0 3. 76 7. 0 Rougher Float..- 2 4 0 1Oleaner 2 2Cleaner 2 3-Oleaner 2 M ezallurgzcal results Assay Percent Distri- Product Weight Units bution Percent Fe Percent Fe SiO, Fe

Heads (assayed) 36.97 Heads (calculated) 100.00 37.67 100.00 Slime 81. 28 31. 33 9. 80 26.08 Rougher Tailing 10. 48 7. 55 0.79 2. 1 Cleaner Tailin 11.04 10. O6 1. 11 2. 95 2 Gleaner Tailin 5. 8B 22. 87 1. 34 3. 57 3 Cleaner Tailin 5. 04 41. 90 35 78 2.11 5. 62 Concentrate 36. 30 61. 76 7 33 22. 42 59. 68 Concentrate and3 Oleaner Tailing 41. 34 59. 34 10. 79 24. 53 65.30

In comparing the results obtained withthe new process described in this invention with the results obtained with V a known conventional process, it is clearly seen that a ven ere a Pre semi ar s bst nt l y all of the iron in the original ore. The product of our process is substantially pure so that undue costs of shipping and smelting a large quantity of siliceous gangue are not incurred. In our process, the slimes, i.e. fine particles in the ground ore need not be removed from the ore before flotation. In the flotation operation, the iron constituents of the slimes are collected in the finished product and the gangue constituents of the slimes arev left behind in the tailings.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

l. A process for the recovery of iron-oxygen compounds from iron bearing ores which comprises grinding said ore to flotation size in the presence of 1 to 5 pounds of a fatty acid material per ton of solids and l to 20 pounds of a hydrocarbon oil per ton of solids, and subjecting the entire mass which has thus been ground to froth flotation.

2. The process of claim 1 characterized further in that said ore is ground to such an extent that 95% thereof will pass a 20 mesh screen.

3. A process for the recovery of iron-oxygen c0mpounds from iron bearing ores which comprises preliminarily comminuting the ore, fine grinding that portion of ground to froth flotation.

4. The process of claim 3 characterized further in that said ore is comminuted to such an extent that 95% thereof will pass a 20 mesh screen, and the preliminarily com- -minuted ore which contains all of the fines is finely ground to such an extent that 95% thereof will pass a 100 mesh screen.

5. A process for the recovery of iron-oxygen compounds from iron bearing ores which comprises preliminarily grinding said ore to flotation size in the presence of 1 to 5 pounds of a fatty acid per ton of solids and 1 to 20 pounds of a mineral oil per ton of solids, subjecting the entire mass which has thus been preliminarily ground to froth flotation, and collecting the portion thereof which floats, fine grinding such collected portion in the presence of up to 5 pounds of a fatty acid per ton of solids and up to 20 pounds of a mineral oil per ton of solids, and subjecting'the entire mass which has thus been finely ground to froth flotation to recover as well the iron-oxygen compounds contained in the slimes of said ore.

6. The process'of claim 5 characterized further in that said ore is' preliminarily ground to such an extent that thereof will pass a 20 mesh screen and said collected portion is ground to such an extent that 95% thereof will pass a mesh screen.

7. The process of claim 1 characterized further in that said fatty acid material is a resin acid.

8. The process of claim 1 characterized further in that said fatty acid material is tall oil.

9. The process of claim 1 characterizedfurther in that said fatty acid material is acidulated cottonseed foots. 10. The process of claim 1 characterized further in that I said hydrocarbon oil is a mineral oil.

11. The process of claim 1 characterized further in that said hydrocarbon oil is a petroleum oil fraction boiling within the range from 450 to 670 F.

12. A process for the recovery of iron-oxygen compounds from hematite ores which comprises grinding said ore to liberation size in the presence'of 1 to 5 poundsof tall'oil per ton of ore and 7 to 10 pounds of a petroleum oil boiling within the range of from 450 to 670 F. per ton of ore, subjecting the entire mass which has thus been ground including the slime fines to froth flotation in water, and collecting the iron-bearing froth which floats;

13. A process for the recovery of iron-oxide compounds from iron bearing ores which comprises grinding said ore to flotation size, adding up to 5 pounds of a carboxylic fatty acid and up to 20 pounds of a hydrocarbonaceous oil per ton of solids to the ore simultaneously with the grinding step, flocculating the iron minerals and iron slimes of the ore during the grinding step by said acid and oil additives, and subjecting the entire mass to froth flotation.

'10 References Cited in the file of this patent UNITED STATES PATENTS 2,014,406 Weed Sept. 17, 1935 2,563,447 Alsop Aug. 7, 1951 2,669,355 Archibald Feb. 16, 1954 OTHER REFERENCES Taggart: Handbook of Mineral Dressing," Wiley 1945, pp. 12-88. 

1. A PROCESS FOR THE RECOVERY OF IRON-OXYGEN COMPOUNDS FROM IRON BEARING ORES WHICH COMPRISES GRINDING SAID ORE TO FLOTATION SIZE IN THE PRESENCE OF 1 TO 5 POUNDS OF A FATTY ACID MATERIAL PER TON OF SOLIDS AND 1 TO 20 POUNDS OF A HYDROCARBON OIL PER TON SOLIDS, AND SUBJECTING THE ENTIRE MASS WHICH HAS THUS BEEN GROUND TO FROTH FLOTATION. 